Automatic fire alarm



L WI UVE SSE & M

c A. ANDERSON. AUTOMATIC FIRE ALARM.

APPLICATXO'N FILED MAY-13. i920- Patented M1. 31,1922;

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Ilium-i INVENTOR ATTORNEYS UNITED STA AUTOMATIC F RE. ALARM.

Application filed May is,

To all whom it may concern:

Beit known'that I, CARL A. ANnnnsoN, a citizen of the United States, anda resident of' North Braddock, in the county of Allegheny-and State ofPennsylvania, have invented a new-andlmproved Automatic Fire Alarm, ofwhich the following is a full, clear, and exact description.

This invention relates to an automatic fire alarm. The object of theinvention is to provid a device which is adapted to be moved around fromplaceto place, as-at various locations within a house or enclosure usedas a residence; and may be employed in a factory or mercantileestablishment and shifted from one place to another which for the timebeing seems to be a special source of danger.

The initiating cause of the alarm is a form of thermostat, and consistsof metal plates constructed and adapted to be warped or deformed from anormal arrangement by a rise in temperature. This initiating cause ofthe alarm is small, light, portable, and controls a purely mechanicalalarm in close proximity, and also controls an electric circuit in whichan electromagnetic alarm is included'and is preferably situated at acentral point or station, either in the same building or at a distancefrom it at a central station.

The drawings illustrate the invention.

Figure 1 is a top plan view;

Figure 2 is a side elevation of the same; and

Figure 3 is a detail.

There is a base plate of sheet steel 5 which is provided with a flange 6on each edge, and flange pieces 7 of sheet metal are bolted across theends to serve as legs. The object in providing these flanges is tostiffen the structure. Fixed to the underside of this base plate 5 is asheet zinc plate 10 having flanges 11 on its opposite edges, and theseflanges are cut away at 12, that is, a point near the center, and thereis a space 13 at each end as well as at the center. This zinc issensitive to variations in temperature, and a rise in temperature in theatmosphere of the room, or from a fire that may be started in thevicinity, will cause the sheet zinc to twist or buckle, and the sheetsteel will either buckle or twist to a greater or lesser extent. Locatedon top of the sheet base plate 5 is a mechanical motor 15 which has aform of clockwork having sheet-metal plates 16 b ltres PAT fcAnL A.ANDERSON, or NORTH BRADDOCK, rnniisYrlvANrA.

Specification of Letters Patent.

1920. Serial No. 382,438. I

Patented Jan. 31, 1552;

ed-together by screws 17 to'form bearings i for arbors18, 19, '20 and21, as shown in Figures 1 and 2.Fastened on top of' the base 5 is agong-22, or an alarm bell, the hammer 23 of whichis supported on thearbor 20. I I

a spring case 24 which is wound by a fixed key 25 on the arbor 18, andthere is an escapement' which terminates'in' anescapement anchor 26.This escapement anchor 26 oscil- There is a'spiral clock spring in latesand is actuated by an escap'em'ent wheel I 27. T he'oscilla-tion ofthisescapement wheel" 27 vibrates the bellhammer'28 and produces anaudiblerespons'e on the-gong 22.? Non mally a stop 28 projects into the path ofan arm 29 fixed on the arbor 20 and holds the spring motor at rest. Uponthe application of heat, the zinc plate 10 is deflected and withdraws astop 30, allowing the stop 28 to fall or move out of the path of thearm29, which releases the arbor 20 and the bell ringing immediatelystarts. This gives an audible alarm anywhere within audible distance ofthe location of thedevice.

For the purpose of giving an alarm at a more remote point, there isprovided an electromagnetic alarm 40. I prefer to use a vibratingelectric bell, and I provide an electric circuit 41 with a battery 42,and the with screw posts 43 and 44 on the metal base piece 5. Connectedto the screw 43 are contact springs 45, and connected to the screw post44 is a contact spring 46. This contact 46 is supported on the arm 47pivoted at 48. A spring 49'engages a projection 52 on the arm 47 andtends to force the contact 46 on the arm 47 into engagement with thecontact 45. This closes the circuit 41-42 and the contacts 45 and 46 areclosed. On the pivoted arm 47 is a flat spring 50 the free end of whichslides along the top of the base 5; and the stop 51 which projects onthe upper surface of the base post plate 5, as seen in Figures 2 and 3,is northe gong 22 and has released the arm 47 which, in response to theaction oi the spring 49, has closedthe contacts .15 and 16, thus closingthe alarm circuit 41 and sounding an alarm on the bell 4O located'at adistant oint.

lVhat I claim is:

1. In an automatic fire alarm, an apertured base plate, a metal platesecured to the base plate and adapted to buckle or warp upon a rise intemperature, a motor driven audible alarm mounted on the base plate,means for holding the motor in check and including a movable member, anda member carried by the second plate and extending through theapertureof said second plate and normally engaging the movable member of thechecking means to hold it; in operative position whereby when the saidplate buckles upon a rise of temperature its member will be: withdrawnfrom the movable member of the checking means torelease the same.

2, In an automatic fire alarm, an apertured.

metal base plate, a second metal plate secured to the under side of thebase plate and adapted to buckle upon a rise of tem perature, a motordriven audible alarm on the base plate, a movable member coacting with amember of the motor to check the same, and a member carried by thesecond platev and extending through the aperture of the base plate andengaging the said movable member. 7

3, In an automatic fire alarm, an apertured metal base plate, a flangedzinc plate secured to the under side of the base plateand provided witha member projecting through the aperture of the base plate,;a

motoron the baseplate, a gong onthebase plate, a hammer opera-ted, bythe motor, an arm on an arbor of the motor, and a movable stop engaging:the member of the zinc plate and held, thereby in engagement with the,

arm of the motorto: hold the said motor at.

rest.

